1939 cadillac V16 hot start problems

[Guest]

This car is running well and has rebuilt carbs, fuel pumps, and electric fuel pump. After driving the car and bring it ot normal operating temperature it will not start. We have gotten it to start at times by pouring fuel directly into the carbs. It is not getting fuel otherwise.<P>Any ideas?

[Guest]

Jack, Do you have your electric fuel pump mounted as close to the gas tank as possible? Also check to see if the carb float is sticking. You might also have a weak electric fuel pump, pull the gas line off of the carb, turn on the pump and see if it has the presser to push the gas thru the stock fuel pump.

[Guest]

Jim,<P>Thank you for the suggestions. The fuel electric fuel pump is located on a frame rail just in front of the rear axle. We do get gas leaking from one carb or another from a sticking float. When you tap the carb it frees up. The man that rebuilt them can't figure out why it they stick. I will have to take them apart myself. I will try to pull a gas line and check out the fuel flow.<P>Jack

[Guest]

Eventhough you have an electric fuel pump I suspect vapor lock. I would try rerouting the fuel line away from heat sources as much as possible.

[Guest]

I agree with Terry...modern fuels have a MUCH higher Reid Vapor Pressure than the fuels available prior to World War Two. And with good reason...higher the vapor pressure..easier it is to start on cold mornings. Modern cars all have fuel injection..which means they all have HIGH PRESSURE fuel pumps INSIDE the gas tank, so there is NO way the fuel can vaporize before it gets to the injectors.<P>Once you resolve your carb. problems, next question is "how fast does it crank over". I used to own the Mae West V-16 ( a '38 Series 90 Formal ). I resolved its slow cranking speed the same way I resolved my '38 Packard Twelve's slow cranking speed...all new heavy copper cables, and a direct "ground" strap right from the battery to the block near the starter..in ADDITION to the existing routing of the "ground". Reason..over the years..corrosion / oxidation can cause poor current transfer from the battery location to the starter.<P>Remember..when these cars were new..they cranked reasonably fast..and fired right away. The trick is..isolate the problem..make it right..and then you will enjoy the kind of high quality motoring the "super cars" of ANY era are capable of.<P>Pete Hartmann<BR>Big Springs, Arizona

[Ed Miller]

I'll throw in my two cents worth of automotive knowledge. I have three interesting vehicles of which two are Full Classics. Neither Full Classic has an electric fuel pump. Rather they come with their original mechanical fuel pump. One has a downdraft and the other an updraft carburetor. Before turning the starter over when hot, slowly depress the gas pedal to the floor and hold it their. Now turn the starter on. It may take a few tries, but even if flooded this should start your engine. If the engine doesn't turn over on the first try, do not lift your foot off the gas pedal or you will compound your problem. Until I used this method of hot starting I dreaded turning my ignition off away from home, but no more. Good luck.

[critterpainter]

On a hot start your carburator bowls are DRY??? and you have to prime the engine??? Sounds like the die cast carb parts are getting porous and leaking the fuel out, either internally or externally. The carb should not drain fuel out while sitting

[Guest]

The reason the bowls could be dry is the heat causing the fuel to evaporat through the vents.